Train horn
Encyclopedia
Train horns are audible warning devices found on most diesel
and electric locomotive
s. Their primary purpose is to alert persons and animals to the presence of a train
, especially when approaching a grade crossing
. They are also used for acknowledging signals given by railroad employees (i.e. during switching
operations).
steam on most railroads, it was realized that the new locomotives were unable to efficiently utilize the steam whistles
then in use.
Early internal combustion locomotives were initially fitted with small truck horns or exhaust-powered whistles, but these were found to be unsuitable and so the air horn
design was scaled up and modified for railroad use.
Train horns are operated by compressed air, typically 125-140 psi (8.6-9.6 bar
), and fed from a locomotive main air reservoir. The flow of air throughout the horn produces an action known as oscillation
. Oscillation in a train horn is accomplished via a diaphragm
assembly enclosed within the power chamber. When air is applied to the horn, the diaphragm vibrates against a nozzle
. The oscillation of the diaphragm against the nozzle produces sound
.
The configuration and overall dimensions of the bell ("bell" being the correct term for the trumpet assembly) determine the fundamental
and frequency produced (measured in hertz
).
North America
n diesel locomotives manufactured prior to the 1990s utilized an air valve actuated by the engineer through the manipulation of a lever or pull cord. Use of this method made possible a practice known as "feathering", meaning that modulation
of the horn's volume
was possible through finer regulation of the air valve.
Many locomotives manufactured during the 1990s made use of pushbutton controls. In addition, several North American locomotives incorporated a sequencer pedal
built into the cab floor beneath the operators position; that when depressed, sounded the grade crossing sequence.
Locomotives of European origin have featured pushbutton control of air horns since the mid-1960s.
Current production locomotives from GE Transportation Systems
and Electro-Motive Diesel have utilized a lever-actuated solenoid valve
.
Swanson sought to develop an air horn which would mimic the sound of a classic steam whistle. Using ancient Chinese musical theory, Swanson produced the six-note model 'H6'. This was impractical for railroad use, due to its relatively large size. Railroad equipment operates over routes restricted by loading gauge
, a difference of only a few inches may prohibit that equipment from operating on the line in question.
Swanson would later refine his 'H6' into the model 'H5'. As the numeric designation indicates, the horn sounds a five-note chord.
In 1950, AirChime introduced the 'M' series, a further improvement on the earlier horns through elimination of unnecessary moving parts. Among the earliest customers of the AirChime 'M' was the Southern Railway, who sought replacement horns for their motive power. In a public relations
effort, the company announced this program through the placement of a full-page advertisement in the May 25, 1951 edition of the Washington Times-Herald
.
Under Swanson's guidance, AirChime would focus on ease of mass production, low maintenance, and reliability in their air horn design, with the development of the 'P' (1953), and 'K' (1954) series.
As of recent, AirChime has been sold to their American licensee, Nathan Manufacturing, Inc., a division of Micro Precision Group, Inc, in Windham, Connecticut
.
Originally founded in 1912 as The American Strombos Co. of Philadelphia, PA, Buell sold modified truck horns for rail use. They were often installed on small locomotives, electric interurban equipment. and railcar
s (for example the Doodlebugs
).
Buell has recently made available a line of air horns specific for railroad equipment.
The Leslie Company (originally of Lyndhurst, New Jersey
, later Parsippany, finally relocating to Tampa, Florida
in 1985) began horn production by obtaining the rights to manufacture the Kockums Mekaniska Verkstad product line of "Tyfon" brand airhorns, marketing these for railroad use beginning in the 1930s. Their model A200 series would later grace the rooftops of countless locomotives, such as the legendary Pennsylvania Railroad GG1, as well as thousands of EMD E
and F-units
. Leslie eventually introduced their own line of multi-note airhorns, known as the "Chime-Tone" series, in direct competition with AirChime.
Poor sales of the Chime-Tones (due to the horns requiring an ample volume
of air) led the Leslie Company to introduce a new line of air horns utilizing interchangeable components while using less air to produce greater sound volume than the earlier "Tyfon" series. Developed by Kockums, this horn utilized a back-pressure power chamber design in order to enhance diaphragm oscillation. Known as the "SuperTyfon" series, these horns would eventually supplant the "Tyfon" in railroad service.
"SuperTyfon" horns were offered in single, dual, triple, quad, and five note configurations.
Today, the company is known as Leslie Controls, Inc.
, and continues to manufacture "SuperTyfon" air horns for the railroad industry.
of the Leslie SuperTyfon design (having taken advantage of a patent
expiration at the time), though their horns employed heavier castings than equivalents from Leslie, and sounding a somewhat richer timbre
as a result.
Sales were brisk (railroads such as Union Pacific
and the Burlington Northern
were notable customers), but ultimately disappointing. Finding themselves increasingly unable to compete in a niche market
dominated by Leslie and AirChime, Prime ceased air horn production c.
1999.
Westinghouse Air Brake Company
(known throughout the 19th and 20th Century as WABCO) was the first to offer air horns specifically for use with railroad equipment, as early as the 1910s. Their model E2 was recognized by many for the deep, commanding tone it produced.
In response to the Leslie multi-note "Chime-Tone" series, Westinghouse offered a bracket to which three of their single-note "honkers" could be bolted onto, achieving the same result as what the Chime-Tones did for Leslie.
Overshadowed later on by Leslie and AirChime, WABCO eventually ceased production of most horns for the North American market.
At present, the company is known as Wabtec, Inc., and continues to offer their line of 'Pneumatic horns' for the export market.
often utilize the same type of air horns as their North American counterparts. Examples from both the Leslie Co. and AirChime Ltd. can be found there.
(FRA), which enforces rail safety regulations, published the final rule on the use of locomotive horns at highway-rail grade crossings. Effective June 24, 2005, the rule requires that locomotive horns be sounded at all public grade crossings at least 15 seconds, but not more than 20 seconds before entering a crossing. This rule applies when the train speed is below 45 mph (70 km/h). At 45 mph or above, trains are still required to sound their horn at the designated location (usually denoted with a whistle post
).
The pattern for blowing the horn remains two long, one short, and one long. This is to be repeated as necessary until the lead locomotive fully occupies the crossing. Locomotive engineers retain the authority to vary this pattern as necessary for crossings in close proximity, and are allowed to sound the horn in emergency situations no matter where the location.
A ban on sounding locomotive horns in Florida
was ordered removed by the FRA after it was shown that the accident rate doubled during the ban. The new ruling preempts any state or local laws
regarding the use of the train horn at public crossings. This also provides public authorities the option to maintain and/or establish quiet zones provided certain supplemental or alternative safety measures are in place, and the crossing accident rate meets government standards.
The following are the required horn signals listed in the operating rules of most North American railroads, along with their meanings. Signals are illustrated by an "o" for short sounds, and "–" for longer sounds. (Note that these signals and their indications are updated to reflect modern practice.)
Those rules marked with an asterisk (*) must be sounded when and/or where applicable. Those signals without an asterisk convey information to employees; they must be used when voice communication is not available.
Exception: Engine horn signals required by rules 14 (b) and 14 (h) do not apply after momentary stops in continuous switching movements.
. Their most common use today is when approaching a level crossing that lacks barriers, and for warning purposes.
Whistle posts are labeled with the letter "P" (for 'Pfeifen').
Common signals are:
Below are a few images depicting the most common mounting applications:
an dwellers (known derisively as NIMBY
s and CAVE People
) have opposed railroad use of the air horn as a trackside warning device.
Residents in some communities have attempted to establish quiet zones, in which train crews are instructed not to sound their horns, except in case of emergency. Given train velocity, as well as the disparity in mass
between railroad equipment and an automobile, truck, or pedestrian
, collisions often occur with little or no allowance for preventative action to be taken by the train crew. The effects of a train colliding with an automobile have been likened to that same automobile striking an empty soda can.
Recent years have seen an increase of horn theft from railroad property. It is believed that the majority of these crimes are perpetrated for the benefit of vehicle customizers and truckers.
Some people collect train horns for their rarity and nostalgic value. Enthusiasts often attend organized events, where specially modified motor vehicles (actual railroad locomotives in some instances) perform runbys. This differs from those who use air horns as a public nuisance, in that permission is often secured from local property owners to conduct such events.
In the world of sports, train horns are often used as goal horns in ice hockey
.
Diesel locomotive
A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...
and electric locomotive
Locomotive
A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...
s. Their primary purpose is to alert persons and animals to the presence of a train
Train
A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...
, especially when approaching a grade crossing
Level crossing
A level crossing occurs where a railway line is intersected by a road or path onone level, without recourse to a bridge or tunnel. It is a type of at-grade intersection. The term also applies when a light rail line with separate right-of-way or reserved track crosses a road in the same fashion...
. They are also used for acknowledging signals given by railroad employees (i.e. during switching
Shunt (railway operations)
Shunting, in railway operations, involves the process of sorting items of rolling stock into complete train sets or consists. The United States terminology is "switching"....
operations).
History and background
As diesel locomotives began to replaceDieselisation
Dieselisation or dieselization is a term generally used for the increasingly common use of diesel fuel in vehicles, as opposed to gasoline or steam engines.-Water Transport:...
steam on most railroads, it was realized that the new locomotives were unable to efficiently utilize the steam whistles
Train whistle
A train whistle or air whistle, , is an audible signaling device on a steam locomotive used to warn that the train is approaching, and to communicate with rail workers....
then in use.
Early internal combustion locomotives were initially fitted with small truck horns or exhaust-powered whistles, but these were found to be unsuitable and so the air horn
Air horn
The air horn is a device designed to create an extremely loud noise. It is usually composed of a pressurized air source coupled to a horn through a valve which allows the device to be turned on and off. Air horns have been installed on large semi-trailer trucks, fire trucks, and some ambulances for...
design was scaled up and modified for railroad use.
Operation
Bar (unit)
The bar is a unit of pressure equal to 100 kilopascals, and roughly equal to the atmospheric pressure on Earth at sea level. Other units derived from the bar are the megabar , kilobar , decibar , centibar , and millibar...
), and fed from a locomotive main air reservoir. The flow of air throughout the horn produces an action known as oscillation
Oscillation
Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...
. Oscillation in a train horn is accomplished via a diaphragm
Diaphragm (acoustics)
In the field of acoustics, a diaphragm is a transducer intended to faithfully inter-convert mechanical motion and sound. It is commonly constructed of a thin membrane or sheet of various materials. The varying air pressure of the sound waves imparts vibrations onto the diaphragm which can then be...
assembly enclosed within the power chamber. When air is applied to the horn, the diaphragm vibrates against a nozzle
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe via an orifice....
. The oscillation of the diaphragm against the nozzle produces sound
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
.
The configuration and overall dimensions of the bell ("bell" being the correct term for the trumpet assembly) determine the fundamental
Fundamental frequency
The fundamental frequency, often referred to simply as the fundamental and abbreviated f0, is defined as the lowest frequency of a periodic waveform. In terms of a superposition of sinusoids The fundamental frequency, often referred to simply as the fundamental and abbreviated f0, is defined as the...
and frequency produced (measured in hertz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
).
North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n diesel locomotives manufactured prior to the 1990s utilized an air valve actuated by the engineer through the manipulation of a lever or pull cord. Use of this method made possible a practice known as "feathering", meaning that modulation
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...
of the horn's volume
Sound pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient atmospheric pressure caused by a sound wave. Sound pressure can be measured using a microphone in air and a hydrophone in water...
was possible through finer regulation of the air valve.
Many locomotives manufactured during the 1990s made use of pushbutton controls. In addition, several North American locomotives incorporated a sequencer pedal
Pedal
The word pedal comes from the Latin and relates to the foot.A pedal is a lever activated by one's foot. The term "foot pedal" is redundant, and should be avoided...
built into the cab floor beneath the operators position; that when depressed, sounded the grade crossing sequence.
Locomotives of European origin have featured pushbutton control of air horns since the mid-1960s.
Current production locomotives from GE Transportation Systems
GE Transportation Systems
GE Transportation, formerly known as GE Rail, is a division of General Electric. The organization manufactures equipment for the railroad, marine, mining, drilling and energy generation industries. It is based in Erie, Pennsylvania. Locomotives are assembled at the Erie plant, while engine...
and Electro-Motive Diesel have utilized a lever-actuated solenoid valve
Solenoid valve
A solenoid valve is an electromechanical valve for use with liquid or gas. The valve is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports...
.
North America
There have been several manufacturers of air horns for railroad use in North America over the years.AirChime, Ltd.
AirChime, Ltd. traces their beginnings through the work of Robert Swanson in 1949. Prior to the early 1950s, locomotives were equipped with airhorns that sounded but a single note.Swanson sought to develop an air horn which would mimic the sound of a classic steam whistle. Using ancient Chinese musical theory, Swanson produced the six-note model 'H6'. This was impractical for railroad use, due to its relatively large size. Railroad equipment operates over routes restricted by loading gauge
Loading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...
, a difference of only a few inches may prohibit that equipment from operating on the line in question.
Swanson would later refine his 'H6' into the model 'H5'. As the numeric designation indicates, the horn sounds a five-note chord.
In 1950, AirChime introduced the 'M' series, a further improvement on the earlier horns through elimination of unnecessary moving parts. Among the earliest customers of the AirChime 'M' was the Southern Railway, who sought replacement horns for their motive power. In a public relations
Public relations
Public relations is the actions of a corporation, store, government, individual, etc., in promoting goodwill between itself and the public, the community, employees, customers, etc....
effort, the company announced this program through the placement of a full-page advertisement in the May 25, 1951 edition of the Washington Times-Herald
Washington Times-Herald
The Washington Times-Herald was an American daily newspaper published in Washington, D.C.. It was created by Cissy Patterson, when she bought the Herald and the Times from William Randolph Hearst, and merged them. The result was a '24 hour' newspaper, with 10 editions per day, from morning to...
.
Windham, Connecticut
Windham is a town in Windham County, Connecticut, United States. It contains the city of Willimantic and the villages of Windham Center, North Windham, and South Windham. The city of Willimantic was consolidated with the town in 1983...
.
Buell Air Horns
Railcar
A railcar, in British English and Australian English, is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coach , with a driver's cab at one or both ends. Some railways, e.g., the Great Western...
s (for example the Doodlebugs
Doodlebug (rail car)
In the United States, doodlebug was the common name for a self-propelled railroad car . While such a coach typically had a gasoline-powered engine that turned a generator which provided electricity to traction motors, which turned the axles and wheels on the trucks, versions with mechanical...
).
Buell has recently made available a line of air horns specific for railroad equipment.
Gustin Bacon Mfg. Co.
The Gustin Bacon Mfg. Co. of Kansas City, MO offered airhorns for use on railroad equipment prior to the Second World War.Leslie Co.
Lyndhurst, New Jersey
Lyndhurst is a township in Bergen County, New Jersey, United States. As of the 2010 United States Census, the township population was 20,554.Lyndhurst was originally formed as Union Township on February 19, 1852 from portions of Harrison Township...
, later Parsippany, finally relocating to Tampa, Florida
Tampa, Florida
Tampa is a city in the U.S. state of Florida. It serves as the county seat for Hillsborough County. Tampa is located on the west coast of Florida. The population of Tampa in 2010 was 335,709....
in 1985) began horn production by obtaining the rights to manufacture the Kockums Mekaniska Verkstad product line of "Tyfon" brand airhorns, marketing these for railroad use beginning in the 1930s. Their model A200 series would later grace the rooftops of countless locomotives, such as the legendary Pennsylvania Railroad GG1, as well as thousands of EMD E
EMD E-unit
EMD E-units were a line of passenger train diesel locomotives built by the General Motors Electro-Motive Division and its predecessor the Electro-Motive Corporation . Final assembly for all E-units was in La Grange, Illinois. Production ran from May, 1937, to December, 1963. The name E-units...
and F-units
EMD F-unit
EMD F-units were a line of Diesel-electric locomotives produced between November 1939 and November 1960 by General Motors Electro-Motive Division and General Motors-Diesel Division. Final assembly for all F-units was at the GM-EMD plant at La Grange, Illinois and the GMDD plant in London, Ontario...
. Leslie eventually introduced their own line of multi-note airhorns, known as the "Chime-Tone" series, in direct competition with AirChime.
Poor sales of the Chime-Tones (due to the horns requiring an ample volume
Volume
Volume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....
of air) led the Leslie Company to introduce a new line of air horns utilizing interchangeable components while using less air to produce greater sound volume than the earlier "Tyfon" series. Developed by Kockums, this horn utilized a back-pressure power chamber design in order to enhance diaphragm oscillation. Known as the "SuperTyfon" series, these horns would eventually supplant the "Tyfon" in railroad service.
Today, the company is known as Leslie Controls, Inc.
Leslie Controls, Inc.
Leslie Controls, Inc., part of the Thermal Fluid Division of Circor International Inc., is a manufacturer of industrial water heaters, control systems and regulators headquartered in Tampa, Florida...
, and continues to manufacture "SuperTyfon" air horns for the railroad industry.
Prime Manufacturing, Inc.
Prime Manufacturing, Inc. had produced locomotive appliances for many years prior to their entry into the air horn market in 1972. Their line of "Pneumatic Horns" was basically a derivativeDerivative work
In United States copyright law, a derivative work is an expressive creation that includes major, copyright-protected elements of an original, previously created first work .-Definition:...
of the Leslie SuperTyfon design (having taken advantage of a patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
expiration at the time), though their horns employed heavier castings than equivalents from Leslie, and sounding a somewhat richer timbre
Timbre
In music, timbre is the quality of a musical note or sound or tone that distinguishes different types of sound production, such as voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the...
as a result.
Sales were brisk (railroads such as Union Pacific
Union Pacific Railroad
The Union Pacific Railroad , headquartered in Omaha, Nebraska, is the largest railroad network in the United States. James R. Young is president, CEO and Chairman....
and the Burlington Northern
Burlington Northern Railroad
The Burlington Northern Railroad was a United States-based railroad company formed from a merger of four major U.S. railroads. Burlington Northern operated between 1970 and 1996....
were notable customers), but ultimately disappointing. Finding themselves increasingly unable to compete in a niche market
Niche market
A niche market is the subset of the market on which a specific product is focusing; therefore the market niche defines the specific product features aimed at satisfying specific market needs, as well as the price range, production quality and the demographics that is intended to impact...
dominated by Leslie and AirChime, Prime ceased air horn production c.
C.
c. may refer to:* Circa: in genealogy and historical writing, c. means circa, and is used when the dates of events are approximately known...
1999.
Westinghouse Air Brake Co.
Westinghouse Air Brake Company
The railway air brake was invented by George Westinghouse of New York state in 1869. Soon after, he moved to Pittsburgh, Pennsylvania, where he established the Westinghouse Air Brake Company on September 28, 1869...
(known throughout the 19th and 20th Century as WABCO) was the first to offer air horns specifically for use with railroad equipment, as early as the 1910s. Their model E2 was recognized by many for the deep, commanding tone it produced.
In response to the Leslie multi-note "Chime-Tone" series, Westinghouse offered a bracket to which three of their single-note "honkers" could be bolted onto, achieving the same result as what the Chime-Tones did for Leslie.
Overshadowed later on by Leslie and AirChime, WABCO eventually ceased production of most horns for the North American market.
At present, the company is known as Wabtec, Inc., and continues to offer their line of 'Pneumatic horns' for the export market.
Australia
Railways in AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
often utilize the same type of air horns as their North American counterparts. Examples from both the Leslie Co. and AirChime Ltd. can be found there.
United States
On April 27, 2005, the Federal Railroad AdministrationFederal Railroad Administration
The Federal Railroad Administration is an agency in the United States Department of Transportation. The agency was created by the Department of Transportation Act of 1966...
(FRA), which enforces rail safety regulations, published the final rule on the use of locomotive horns at highway-rail grade crossings. Effective June 24, 2005, the rule requires that locomotive horns be sounded at all public grade crossings at least 15 seconds, but not more than 20 seconds before entering a crossing. This rule applies when the train speed is below 45 mph (70 km/h). At 45 mph or above, trains are still required to sound their horn at the designated location (usually denoted with a whistle post
Whistle post
A whistle post , in railroad usage, is a sign marking a location where a locomotive engineer is required to sound the horn or whistle.-United States:...
).
The pattern for blowing the horn remains two long, one short, and one long. This is to be repeated as necessary until the lead locomotive fully occupies the crossing. Locomotive engineers retain the authority to vary this pattern as necessary for crossings in close proximity, and are allowed to sound the horn in emergency situations no matter where the location.
A ban on sounding locomotive horns in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
was ordered removed by the FRA after it was shown that the accident rate doubled during the ban. The new ruling preempts any state or local laws
Federal preemption
Federal preemption refers to the invalidation of US state law when it conflicts with Federal law.-Constitutional basis:According to the Supremacy Clause of the United States Constitution,...
regarding the use of the train horn at public crossings. This also provides public authorities the option to maintain and/or establish quiet zones provided certain supplemental or alternative safety measures are in place, and the crossing accident rate meets government standards.
The following are the required horn signals listed in the operating rules of most North American railroads, along with their meanings. Signals are illustrated by an "o" for short sounds, and "–" for longer sounds. (Note that these signals and their indications are updated to reflect modern practice.)
Those rules marked with an asterisk (*) must be sounded when and/or where applicable. Those signals without an asterisk convey information to employees; they must be used when voice communication is not available.
| Rule | Sequence | Indication | |
|---|---|---|---|
| 14 (a) | o | Applying air brakes while standing. | |
| 14 (b) | * | – – | Proceeding. Releasing air brakes. |
| 14 (f) | * | o o – | Acknowledging a flagman's stop signal. |
| 14 (g) | * | o o | Acknowledging any signal not otherwise provided for. |
| 14 (h) | * | o o o | Backing up. |
| 14 (j) | o o o o | Calling for signals. | |
| 14 (l) | * | – – o – | 1. Trains or engines approaching public highway grade crossings shall sound the horn at least 15 seconds, but no more than 20 seconds before the lead engine enters the crossing. Trains or engines travelling at speeds greater than 45 mph shall begin sounding the horn at or about, but not more than, one-quarter mile (1,320 feet) in advance of the nearest public crossing. Even if the advance warning provided by the horn will be less than 15 seconds in duration. This signal is to be prolonged or repeated until the engine or train occupies the crossing; or, where multiple crossing are involved, until the last crossing is occupied. 2. Approaching tunnels, yards, or other points where railroad workers may be at work. 3. Passing standing trains. |
| 14 (m) | * | o | Approaching passenger station. |
| 14 (o) | o – | Inspect train for a leak in brake pipe system or for brakes sticking. | |
| 14 (p) | * | Succession of sounds | Warning to people and/or animals. |
| 14 (q) | * | – o | When running against the current of traffic: 1. Approaching stations, curves, or other points where view may be obscured: and 2. Approaching passenger or freight trains and when passing freight trains. |
Exception: Engine horn signals required by rules 14 (b) and 14 (h) do not apply after momentary stops in continuous switching movements.
Germany
Horn signals are regulated in the Zp category of the Eisenbahn-Bau- und BetriebsordnungEisenbahn-Bau- und Betriebsordnung
The Eisenbahn-Bau- und Betriebsordnung or EBO is a German law specifying rules and regulations for railways....
. Their most common use today is when approaching a level crossing that lacks barriers, and for warning purposes.
Whistle posts are labeled with the letter "P" (for 'Pfeifen').
Common signals are:
| Sequence | Meaning |
|---|---|
| _ | Zp 1 - Generic "Attention" signal. |
| o | Zp 2 - Tighten handbrakes. |
| o o | Zp 3 - Strongly tighten handbrakes. |
| _ _ | Zp 4 - Loosen handbrakes |
| ooo ooo ooo | Zp 5 - Emergency. Brake immediately. |
| _ o _ | Zp 11 - Come. Used to call out for train staff. |
France
Train horns are sounded where a whistle post (marked with the letter "S" for "siffler") is present. If the whistle post is labelled "J" (meaning "jour"), the horn is only to be sounded between 0700 and 2000. Horns must also be sounded when passing an oncoming train, and shortly before reaching the last car of the train.India
Locomotive horns are sounded before trains enter a station and upon departure, passing over bridges as well as road crossings.United Kingdom
UK diesel and electric locomotives are usually fitted with two-tone horns and, in the past, both tones were routinely used. However, because of noise complaints, new rules were introduced in 2007:- The introduction of a night time quiet period, between 2300 and 0700 when trains will no longer routinely sound their horns at whistle boardsWhistle postA whistle post , in railroad usage, is a sign marking a location where a locomotive engineer is required to sound the horn or whistle.-United States:...
(they will always sound their horns when people are seen on the track) - That where the technology is available, drivers should only use the low tone from the two tone horn at whistle boards.
- For all new or replacement train horns on trains capable of travelling up to 160 km/h a much lower minimum sound pressure level has been established – and a maximum sound level has been introduced (min 101dB and max 106dB)
Placement on locomotives
As many individuals do with their personal vehicles, railroads order locomotives with different options in order to suit their operating practices. Air horns are no exception, and railroad mechanical forces mount these on locomotives where they are deemed most effective at projecting sound, and for ease of maintenance.Below are a few images depicting the most common mounting applications:
In railroad use
Due to the encroachment of development, some suburbSuburb
The word suburb mostly refers to a residential area, either existing as part of a city or as a separate residential community within commuting distance of a city . Some suburbs have a degree of administrative autonomy, and most have lower population density than inner city neighborhoods...
an dwellers (known derisively as NIMBY
NIMBY
NIMBY or Nimby is an acronym for the phrase "not in my back yard". The term is used pejoratively to describe opposition by residents to a proposal for a new development close to them. Opposing residents themselves are sometimes called Nimbies...
s and CAVE People
CAVE People
CAVE People is a pejorative acronym for citizen activists who regularly oppose any changes within a community...
) have opposed railroad use of the air horn as a trackside warning device.
Residents in some communities have attempted to establish quiet zones, in which train crews are instructed not to sound their horns, except in case of emergency. Given train velocity, as well as the disparity in mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
between railroad equipment and an automobile, truck, or pedestrian
Pedestrian
A pedestrian is a person traveling on foot, whether walking or running. In some communities, those traveling using roller skates or skateboards are also considered to be pedestrians. In modern times, the term mostly refers to someone walking on a road or footpath, but this was not the case...
, collisions often occur with little or no allowance for preventative action to be taken by the train crew. The effects of a train colliding with an automobile have been likened to that same automobile striking an empty soda can.
Recent years have seen an increase of horn theft from railroad property. It is believed that the majority of these crimes are perpetrated for the benefit of vehicle customizers and truckers.
In non-railroad use
In the world of sports, train horns are often used as goal horns in ice hockey
Ice hockey
Ice hockey, often referred to as hockey, is a team sport played on ice, in which skaters use wooden or composite sticks to shoot a hard rubber puck into their opponent's net. The game is played between two teams of six players each. Five members of each team skate up and down the ice trying to take...
.
Audio samples
The following are samples of select air horns as used in North American railroad service:See also
- Air hornAir hornThe air horn is a device designed to create an extremely loud noise. It is usually composed of a pressurized air source coupled to a horn through a valve which allows the device to be turned on and off. Air horns have been installed on large semi-trailer trucks, fire trucks, and some ambulances for...
- Hancock air whistleHancock air whistleThe Hancock air whistle was a railroad whistle intended for use on North American diesel locomotives in place of the standard air horn.- History :...
- Steam whistleSteam whistleA steam whistle is a device used to produce sound with the aid of live steam, which acts as a vibrating system .- Operation :...
- Whistle postWhistle postA whistle post , in railroad usage, is a sign marking a location where a locomotive engineer is required to sound the horn or whistle.-United States:...
External links
- Five Chime Consultants - The original online spotters' guide to diesel locomotive horns as used throughout the United States and Canada. Fully illustrated with audio samples and background information on each horn.
- Locomotive Horns - Extensive guide to collecting diesel locomotive air horns, recommended viewing for new and established collectors alike.